THE BRAIN OF THE EARTH 



nine hundred and fifty millions of particles in a 

 cylinder one-fourth of an inch in diameter and 

 half an inch long, — the little child's thimble, 

 the approximate measure of a gram. Is he 

 going in for ordinary summer and autumn vege- 

 tables, — corn and cabbage and potatoes and 

 squash and eggplant and the delicious small 

 fruits that may fill in many a spare spot and 

 line many a vacant compartment in his pocket- 

 book? Then there must be at least two billion 

 additional particles in each gram of his soil, 

 or good results will fail to come. If he is a 

 wheat planter, he may be sure the crop will 

 be lean and weak if there are not at least ten 

 billion, two hundred millions of particles ; while, 

 for wheat and grass lands combined, full four- 

 teen billion, seven hundred millions of separate 

 particles must be found in the little thimble. 



If the farmer has but just settled upon his 

 new land, ignorant of its measure of productiv- 

 ity, he may as well move onward to some 

 other region if the soil beneath his feet does 

 not have at least one billion, seven hundred 

 million of particles per single gram. These 

 minute particles must also contain all of the 

 elements of fertility in a well-balanced form. 



11 



